One of the realities is we're going to have a smaller geographical city. You're not going to be able to build on all of the ground, and we're going to lose population. We'll have to provide housing for 100,000 to 150,000, and we might lose 100,000 or more.... The goal should be to provide permanent housing in a more dense fashion on high ground, which would mean mixed-income housing.

You should reorganize the public school system, taking advantage of models of success that have been developed around the country. As you look at the grid system, putting in high-speed broadband could give us a real advantage as a city. And you should take a look at light rail, both inner-city (the streetcar systems) and out to the airport, which is a project that could help people move out of the city in case of another catastrophe.

How can design enhance culture?

We need to build on our cultural assets. One project I had worked on was to develop 4,000 acres [in a way that would] make the city more like a Paris - an Afro-Caribbean Paris. One in which you expanded development into poor neighborhoods, to increase the amount of terrain that locals and visitors could safely navigate.... In Paris, you can walk 15 or 20 blocks and have an interesting experience the whole way. We need to develop microprojects to revitalize the poorer neighborhoods as well as the monumental projects that we do all the time.

Who should be involved?

We need to do everything with velocity.... You invite in the Urban Land Institute and the Brookings Institution and others, and have them work with locals, then stay up all night for a few weeks, set out a plan, and go. You want to have that national and international good thinking, but it needs to be combined with locals who understand the turf.

Old character, newer values

Reed Kroloff, dean of the Tulane University School of Architecture in New Orleans

What needs to be preserved?

New Orleans has a distinctive and unusual urban pattern. It's like a fine grain on a piece of wood. When the French originally laid out New Orleans, they tried to give as many planters riverfront exposure as they could ... and ended up with a city made up of long, narrow lots. That fine grain is very distinctive, and it's critical for maintaining the character of New Orleans. The beauty is that it makes automatically for a dense, urban, walkable city. It's among the better-designed, better-laid-out, quirkier, more humane cities in this country.

What are the dangers?

The worst thing that could happen is a bad 21st-century version of a great 19th-century home. It would be a bad cartoon version of what New Orleans actually is. We should be careful about creating something that not only respects the old city, but learns from it, because it is sustainable. There's no reason a neighborhood of single-family homes can't be replaced by multi- family homes, or multifamily homes within mid-rise buildings, and still maintain that character: a long, skinny, 12-story building that's elegant and beautiful.

Where should the city rebuild?

We could bring higher buildings into the downtown area or along the riverfront without damaging the character of the city. There are large pieces of blank land in the center that could be developed into dense residential, mixed-use areas.

What's the opportunity?

Why can't New Orleans become the center for sustainable modular housing in the future?... It's an industry that requires working people at every level of economic and educational strata. Why can't we be the people to design "green" modular housing? Those are immediate jobs that become permanent jobs.

From preposterous to conceivable

Kristina Ford, New Orleans city planner from 1992 to 2000, then head of the New Orleans Building Corp., now professor of land-use planning at Bowdoin College in Brunswick, Maine

What does the city need to preserve?

The thing about New Orleans was its jumble of culture, races, income groups, ages: We all lived in a big jumble that even if you saw a big mansion on St. Charles Avenue, you wouldn't have to go very far and you'd come to a really modest Creole cottage in some stage of disrepair. That kind of mixture is what gave the city its grit.... To live in New Orleans was to know your life was very provisional. You can't live below sea level and not understand it could all come washing in over you. It made people in New Orleans very tolerant of each other.

What should be done with the Lower Ninth Ward, scene of some of the worst flooding?

If, when I was head of city planning, I had gone to the mayor and said, "The Lower Ninth is in trouble, we need to get people to move out temporarily, fill in the land so it's higher, and rebuild," it would have been preposterous. Now it's something that could be done. Or, maybe that idea is preposterous, and then you say, maybe we decide the Lower Ninth is a catch basin whenever there's a flood. It's where you park school buses or put public works, but don't let anybody live there. So when you talk about rebuilding the Ninth Ward, you don't mean the physical location, you mean the people who lived there.

How do you bring people back?

There should be a rule that says some percentage of the labor force - say 20 percent - of anyone who gets a [rebuilding] contract has to be native New Orleanian.... That gets New Orleanians back who know something about what New Orleans used to look like.

There are some people who will think that now that some of these poorer people have been dispersed into the population, they should stay dispersed. I've heard people say, "Let's make it an upper-middle-class yuppie town." I hope that doesn't happen.

'Smart' strategy

Robert Bea, professor of civil engineering at the University of California in Berkeley and a former New Orleans resident

What can we learn from others?

You could do what the Dutch did and build a massive set of defenses with dikes, canal systems, and pumps. All of that was done in reaction to the 1953 incredible North Sea storm that flooded the entire country. Because they are not a rich country, they had to do it smart. But you can't build a 100-foot wall around New Orleans, not only because of the culture but [because of] the soft soil as well. The best you can do is probably build [the levees] up another 10 to 15 feet.

How should the flow of water be regulated?

Building up the levees is one part of the solution, but the canals should be buried under the streets and replaced by large culverts and modern pumping stations placed on high ground, not low ground. You've got a collection of tunnels, to carry and collect water, [dating] from 1937.... The area's natural defense mechanisms have been eroded away. The barrier island needs to be put back in place and the wetlands restored. That can be done by the Army Corps of Engineers. You've got to let the Mississippi River work [naturally].

How should funds be spent?

The government is getting ready to dump $200 billion into this problem, but not a ... dime should be put into re-creating what was done in the past. Usually in American disasters such as this, we see knee-jerk reaction and brute force. But if we do it smart, we can in fact provide the protection that is needed. This is our opportunity to do things a little differently. Yes, New Orleanians will still be living below sea level, but so are the Dutch. It took them until the mid-'70s to get their system in place. No one should expect this to happen overnight.